The invention relates to apparatus used for enabling persons incapable of speech to communicate. The apparatus of the present invention is specifically related to apparatus utilized by persons who in addition to a speech impediment also have severe mobility problems. Body motions of such individuals may be severely limited through either physical or psychological disorders. However, such individuals are frequently capable of moving at least one muscle. The movement of one muscle can thus be utilized to activate and deactivate a single switch. Alternatively, breath-actuated switches have been utilized to actuate prior art communication devices.
One type of non-oral communication apparatus already in use utilizes a pair of relays to change the position of a signal along both a column and a row. Messages or specific letters correspond to each column and row coordinate. Such devices, which store complete messages at coordinates, are limited in the number of messages which can be communicated to the size of the matrix formed by the columns and rows. The messages communicated by such devices generally are either illuminated on a board or transmitted to a printing device. A small matrix thus limits the number of messages which can be communicated. In prior art devices which utilize small matrices, the messages are frequently limited to urgent patient needs, such as a nurse call, a request for water, or an indication of pain.
As the matrix size increases to increase the number of messages which can be communicated, the problem of time consumption in reaching a specific column and row location through a relay mechanism increases. In a device disclosed in U.S. Pat. No. 4,048,439 to Gabus, each coordinate corresponds to one or two letters instead of a complete message. The letters can be selected and printed by the operator. This type of device allows an operator to create his own messages. However, time consumption becomes a problem because each column-row coordinate is assigned only one or two letters.
Another type of prior art communication device utilizes a keyboard to transmit a message in one form or another. However, a certain amount of mobility and dexterity of the operator is required to operate the keyboard. A keyboard type of apparatus is unsuitable for use by persons with severe mobility problems. A typewriter is of this type. Another keyboard type of apparatus, such as is shown in U.S. Pat. No. 3,925,779 to Gerstenhaber, utilizes a calculator type of keyboard and display wherein a plurality of messages are correlated to the various keys. The number of messages, however, is limited to the number of keys on the apparatus. The versatility of the calculator type of apparatus can be increased by the use of programmable circuit boards, however, for any circuit board, the number of messages is limited to the matrix size of the keys.
Another type of apparatus, such as is shown in U.S. Pat. No. 3,507,376 to Kafafian, uses finger contacts to control an X-Y keyboard to print messages. A considerable amount of dexterity is required to use this type of apparatus, since selective motion and contact between all of the fingers of an operator is required. Hence, such an apparatus cannot be used by seriously disabled persons with extreme mobility impairment.
In the types of apparatus described above wherein the message is not printed, a user is limited in the manner in which he can communicate. A person must be present to read the message prior to the user's communicating another message through the apparatus. A user is thus under stress to actuate the apparatus and communicate while a person is present. Frequently, seriously handicapped persons are alone for long periods of time in a hospital or nursing home and visitors are present for only a short period of time. Hence, severe pressure is placed upon the handicapped person to accurately operate the apparatus in order to compose and communicate as much as possible within the short period of time.
An apparatus which can print messages therefore has a distinct advantage over apparatus which cannot print. In the prior art devices discussed above which utilize printers, however, either the number of messages which could be printed is limited or the devices are time-consuming to utilize.
Another type of communication device has recently become available which increases the number and variety of messages. This device reproduces phonetic sounds to make up words. The device stores a number of basic complete words, as well as basic phonetic sounds. The words and sounds are coded and an operator accesses the words or sounds via either a keyboard or a single switch mechanism. Such a phonetic device, however, also suffers from the above-discussed deficiencies of nonprinting apparatus. That is, the presence of an individual to hear the message is required and the device is time-consuming to use. The user is thus placed under stress to accurately utilize the apparatus and compose messages in a relatively short period of time.